The present invention relates to a type of automatic gas spray device, particularly to one that automatically spray irritative gas in case of an attack, to hinder criminals.
U.S. Pat. No. 5,034,730, issued to the present inventor, discloses an automatic gas spray device for protection against criminals which can be installed at various locations to automatically spray irritative gas activated by an electronic control main unit and a solenoid sensor for hindering criminals in case of an attack. This automatic gas spray device is effective in use, however, it still has some drawbacks. One drawback of this device is that the electronic control main unit and the solenoid sensor are difficult to install. Another drawback is that the housing must be dismantled when replacement of the gas tank is needed. Further, this structure of automatic gas spray device has no indicator means to indicate the current electric quantity of the battery power supply and the current amount of gas in the gas tank.